package main

import "fmt"

type DataWriter interface {
	WriteData(data interface{}) error
}

type file struct {

}

func (d *file) WriteData(data interface{}) error {
	fmt.Print("writeData:", data)
	return  nil
}


func main() {
	f := new(file)

	//var writer DataWriter

	//writer = f

	//writer.WriteData("11111")
	f.WriteData("2222")
}
